You can also try a lubricating product like WD-40. Apply it to the area around the threaded fitting or joint and wait a few minutes for the product to make its way into the connection. Then use the pipe wrench or your hands to twist the pipe counterclockwise until it is loose enough to remove.
use two pipe wrenches. one to hold the pipe and another to loosen the cap. if you can't move it with the wrench alone, use a cheater bar. the line is probably no larger than 3/4'' and unless it is completely rusted i don't see why 2 pipe wrenches wouldn't work. buy the caps and pipe dope for the other two lines.
You can purchase a variety of thread-loosening lubricants to dissolve rust, or you can lubricate with plumber's wax. In the end, however, it requires heavy wrenches with long handles and a certain amount of brute force to make headway when separating the most tightly-locked joints.
Turning the nut or tap clockwise will tighten it whilst turning it counter clockwise will loosen it.
Pipe Wrenches
One type of adjustable wrench is a pipe wrench, the workhorse of a plumber's toolkit. Available in various sizes, they are designed to grip and turn pipes and fittings. Their adjustable jaws provide a strong grip and make loosening or tightening threaded pipes a breeze.
However, this versatile and widely-used lubricant and penetrating oil can be surprisingly effective in tackling various common plumbing problems. There are many times that customers call a plumber in Glasgow when in actual fact, a simple spray of WD40 is all they needed to fix the issue.
Use Heat To Expand the Metal
Heat causes metal to expand slightly, which may be enough to break the nut free. You can add heat safely with a hair dryer or heat gun. If you're using an open flame, such as a propane torch, be extremely cautious and shield anything flammable with a flame-resistant fabric.
Get a heat gun (electric, not a flame type) and heat the piece of pipe inside the fitting, very carefully, without overheating the fitting itself, at the same time use a small, flat-bladed screwdriver to start to separate the pipe inside the fitting and the fitting itself.
Loosening Galvanized Pipe Fittings
Loosen the connection by turning the nut counter-clockwise. Then, hold the fitting securely with one of the pipe wrenches and use the other pipe wrench to turn the loose piece of pipe that is connected to the fitting.
Use your hair dryer to heat up the valve body to melt any gunk and grime that's built up and solidified into an adhesive. Once you can feel the valve turning, wiggle it back and forth to let the gunk and grime wash away. Use your wrench to loosen the bonnet or packing nut.
Mix 1/3rd of a cup of bicarbonate of soda with 1/3rd of a cup of vinegar in a measuring cup. It will fizz immediately, and you should waste no time pouring it down the clogged drain. The fizzing action will help to remove the gunk, hair, and grime that has built up in the blocked drain pipe.
We recommend putting a cloth over the handle and using your hand to slowly rock the stuck valve back and forth to loosen it. Keep doing this until the valve can be completely opened and closed. If the valve won't turn after trying this, grab a pair of Channellock pliers.
If you are working on a PVC pipe P-trap, you should be able to loosen the nuts on either end with a little bit of strength. Then, turn them counterclockwise to loosen and unscrew. Make sure that the nuts and your rubber gloves are dry.
Commonly known as CRC, penetrating oil should be your first step in trying to loosen a nut, bolt, or screw. Spray the fastener and leave for 10 – 15 minutes to allow the oil time to penetrate the threads of the bolt or screw. Then use a wrench or screwdriver to undo the fastener.
Vinegar is both safe and beneficial to pour down your drain.
Plumbers grease is a versatile, durable, and waterproof lubricant that is specifically designed to help protect and prolong the life of your plumbing fixtures. It is made from a variety of materials, including petroleum and synthetic oils.
Tongue and groove pliers.
These pliers have a slip-joint design that allow the jaws to open wide and grab bigger things.
Using the right sized spanner or an adjustable wrench, tighten the nut a little, then give it a wriggle before trying to loosen it again (remember righty tighty, lefty loosey!). Turn on the heat. Heat makes metal expand, so applying a little heat to the nut could make it expand enough to loosen.